console.log({}.toString())
console.log({}.valueOf())

console.log([].toString()) //' '
console.log([].valueOf())


let obj = {}
let arr = [2, 3, 2]
// 获取原型方法
console.log(arr.__proto__)
console.log(obj.__proto__)
console.log(arr.constructor.prototype)
console.log(Object.getPrototypeOf(arr))


